《2025年一步名校单元测试卷六年级数学上册冀教版》

五、解方程。
$4:5=28:x$ $\frac{1}{6}:\frac{8}{9}=x:\frac{16}{51}$ $x+50\%x=42$
$x÷ 80\%=\frac{15}{28}$ $25\%+x=\frac{7}{12}$ $x-28\%x=21.6$
$1-25\%x=\frac{1}{4}$ $x÷ \frac{1}{7}=15× 40\%$ $x÷ \frac{1}{8}-\frac{1}{2}=150\%$
$75\%x-\frac{3}{5}x=6$ $\frac{2}{3}x÷ 25\%=\frac{12}{7}$ $\frac{5}{9}x-\frac{3}{4}× \frac{1}{3}=25\%$

答案： 五、解:$4:5 = 28:x$
$4x = 28 × 5$
$x = 140 ÷ 4$
$x = 35$
解:$\frac{1}{6} : \frac{8}{9} = x : \frac{16}{51}$
$\frac{8}{9}x = \frac{1}{6} × \frac{16}{51}$
$x = \frac{8}{153} ÷ \frac{8}{9}$
$x = \frac{1}{17}$
解:$x ÷ 80\% = \frac{15}{28}$
$x = \frac{15}{28} × 0.8$
$x = \frac{3}{7}$
解:$x + 50\% x = 42$
$1.5x = 42$
$x = 28$
解:$x - 28\% x = 21.6$
$72\% x = 21.6$
$x = 30$
解:$25\% + x = \frac{7}{12}$
$x = \frac{7}{12} - \frac{1}{4}$
$x = \frac{1}{3}$
解:$1 - 25\% x = \frac{1}{4}$
$\frac{1}{4}x = \frac{3}{4}$
$x = 3$
解:$x ÷ \frac{1}{7} = 15 × 40\%$
$x = 6 × \frac{1}{7}$
$x = \frac{6}{7}$
解:$x ÷ \frac{1}{8} - \frac{1}{2} = 150\%$
$8x = 2$
$x = \frac{1}{4}$
解:$\frac{2}{3}x ÷ 25\% = \frac{12}{7}$
$\frac{8}{3}x = \frac{12}{7}$
$x = \frac{9}{14}$
解:$\frac{5}{9}x - \frac{3}{4} × \frac{1}{3} = 25\%$
$\frac{5}{9}x - \frac{1}{4} = \frac{1}{4}$
$\frac{5}{9}x = \frac{1}{2}$
$x = \frac{9}{10}$

六、求阴影部分的周长。

答案： 六、$1.3.14 × 4 = 12.56$
$2.\frac{1}{2} × 3.14 × 4 + \frac{1}{2} × 3.14 × 8 + \frac{1}{2} × 3.14 × (4 + 8) = 37.68$
$3.3.14 × 6 + \frac{1}{2} × 3.14 × (6 × 2) + 6 × 2 = 49.68$
$4.\frac{1}{4} × 3.14 × (5 × 2) + \frac{1}{4} × 3.14 × (3 × 2) + 2 × (5 - 3) = 16.56$
$5.100 × 2 + 80 + \frac{1}{2} × 3.14 × 80 = 405.6$
$6.3.14 × 4 + \frac{1}{4} × 3.14 × (4 × 2) = 18.84$